Preheat oven to 375. Lightly coat an 11-by-17-inch baking pan with cooking spray, and line with parchment; set aside. Have ready a pastry bag fitted with a #11 plain tip. Spoon jam into a medium bowl, and beat with a rubber spatula to smooth out texture; set aside. In a medium bowl, whisk flour, cornmeal and salt; set aside.

In the bowl of an electric mixer fitted with the paddle attachment, combine butter and sugar, and beat on medium speed until light and fluffy, 2 to 3 minutes. Add eggs one at a time, beating until smooth after each addition. Reduce speed to low, add reserved flour mixture, and beat until thoroughly combined. Remove 1 3/4 cups of the dough; use it to fill the prepared pastry bag. Fold the end over to keep the dough from drying out; set aside.

Using an offset spatula, spread the remaining dough into the prepared pan as evenly and smoothly as possible. Bake until golden brown, about 20 minutes.

Remove pan from oven, and transfer to a heat-proof surface. Using an offset spatula, spread jam on top in an even layer. Using the prepared pastry bag, pipe parallel line of dough spaced 1 inch apart over the jam. Pipe perpendicular lines of dough at 1-inch intervals over the first lines. Place in oven, and bake until golden, 20 to 25 minutes, rotating halfway through. Transfer to a wire rack to cool. Cut into 1 1/2-by-3-inch bars or 3-inch squares.